需求：
1、查
输入：www.oldboy.org
获取当前backend下的所有记录
2、新建
输入：
arg = {
'bakend': 'www.oldboy.org',
'record':{
'server': '100.1.7.9',
'weight': 20,
'maxconn': 30
}
}
3、删除
输入：
arg = {
'bakend': 'www.oldboy.org',
'record':{
'server': '100.1.7.9',
'weight': 20,
'maxconn': 30
}
}
分析：
1、输入是字典模式的字符串，需要把字符串转换为字典，对字典进行处理
2、对文件进行copy，读取，覆盖写操作，还要设置标志，进行区分处理
3、函数的调用
功能查：
def fetch(backend):
#取出backend相关的server信息
result = [] #定义结果列表
with open("haproxy","r",encoding="utf-8") as f: #循环读取文件
flag = False #标记为假
for line in f :
#以backend开头
line = line.strip()
if line.startswith("backend") and line == "backend %s" %backend:
flag = True #读取到backend开头的信息，标记为真
continue #直接返回到for语句
#如果遇到下一个backend开头的语句，直接break跳出for语句，因为数据拿完了
if flag and line.startswith("backend"):
flag = False
break
#server信息添加到result列表
if flag and line.strip():
result.append(line)
return result
实现代码：
import shutil
import json
def list_function():
print("Please choice the ID of a action.".center(50,"#"))# 50g个字符，提示在中间，不够的#补足
print("【1】.Fetch haproxy backend infomation.")
print("【2】.Add haproxy backend infomation.")
print("【3】.Delete haproxy backend infomation.")
print("【q】.Delete haproxy backend infomation.")
def fetch(backend):
#取出backend相关的server信息
result = [] #定义结果列表
with open("haproxy","r",encoding="utf-8") as f: #循环读取文件
flag = False #标记为假
for line in f :
#以backend开头
line = line.strip()
if line.startswith("backend") and line == "backend %s" %backend:
flag = True #读取到backend开头的信息，标记为真
continue #直接返回到for语句
#如果遇到下一个backend开头的语句，直接break跳出for语句，因为数据拿完了
if flag and line.startswith("backend"):
flag = False
break
#server信息添加到result列表
if flag and line.strip():
result.append(line)
return result
def writer(backend,record_list):
with open("haproxy","r") as old,open("haproxy_new","w") as new:
flag = False
for line in old:
if line == "backend %s " %backend:
flag = True
new.write(line)
for new_line in record_list:
new.write(""*4 + new_line + " ")
continue
if flag and line.strip().startswith("backend"):
flag = False
new.write(line)
continue #跳到下一次循环，防止backend写两次
if line.strip() and not flag:
new.write(line)
def add(backend, record):
global change_flag
record_list = fetch(backend) #查找是否存在backend
if not record_list and record_list != []: #backend不存在同时record_list是空列表
with open('haproxy','r') as old, open("haproxy_new",'w') as new:
for line in old:
new.write(line)
new.write(" backend " + backend + " ")
new.write(" "*4 + record + " ")
print(" 33[32;1mAdd done 33[0m")
change_flag = True
else: #backend存在
if record in record_list:
print("Record already in it,Nothing to do!")
change_flag = False
else: #backend存在，record不存在
record_list.append(record)
writer(backend,record_list)
print(" 33[32;1mAdd done 33[0m")
change_flag = True
def delete(backend, record):
global change_flag
record_list = fetch(backend)
if not record_list:
print("Not match the backend,no need delete!".center(50,"#"))
else:
if record in record_list:
record_list.remove(record)
writer(backend,record_list) #写入
print(" 33[31;1mDelete done 33[0m")
change_flag = True
else: #backend存在，record不存在
print("Only math backend,no need delete!".center(50,"#"))
change_flag = False
return change_flag
def output(servers):
#输出指定backend的server信息
print("Match the server info:".center(50,"#"))
for server in servers:
print(" 33[32;1m%s 33[0m" % server)
print("#".center(50,"#"))
def operate(action):
global change_flag
if action == "fetch":
backend_info = input("Input backend info:")
result = fetch(backend_info) #取出backend信息
if result:
output(result) #输出获取到的server信息
else:
print(" 33[31;1mNot a match is found! 33[0m")
elif action is None:
print(" 33[31;1mNothing to do! 33[0m")
else:
backend_record = input("Input backend info(dict):") # 输入的是字符串,
backend_record_dict = eval(backend_record)
backend = backend_record_dict['backend']
record = backend_record_dict['record']
record = "server %s %s weight %s maxconn %s" % (record['server'], record['server'],
record['weight'], record['maxconn'])
if action == "add":
add(backend,record)
elif action == "delete":
delete(backend,record)
if change_flag is True: #文件有修改，才进行文件更新
shutil.copy("haproxy","haproxy_old")
shutil.copy("haproxy_new","haproxy")
result = fetch(backend)
output(result) #输出获取到的server信息
def judge_input():
#判断输入功能编号，执行相应步骤
input_info = input("Your input number:").strip()
if input_info == "1": #查询指定backend记录
action = "fetch"
elif input_info == "2":
action = "add"
elif input_info == "3":
action = "delete"
elif input_info == "q" or input_info == "quit":
exit("Bye,thanks!".center(50,"#"))
else:
print(" 33[31;1mInput error! 33[0m")
action = None
return action
def main():
exit_flag = False
while exit_flag is not True:
global change_flag
change_flag = False
list_function()
action = judge_input()
operate(action)
if __name__ == '__main__':
main()